In related art techniques, in a hybrid vehicle provided with the motor/generator at an output shaft of the engine for getting torque assistance, upon an engine stall start or an engine racing, the torque assistance by the motor/generator is forbidden. With this operation, decrease in voltage of battery etc. is prevented, thereby bringing improvement in fuel economy of the engine (see, for example, Patent Document 1).
Here, “racing” used in the present specification indicates engine racing or engine rpm surge in which when the accelerator depression operation is done in the state in which the engine is in the no-load state at the time of acceleration including the vehicle start, an engine rotation speed (an engine rpm) increases according to the accelerator depression operation.